SIMSON, THOMAS (1696–1764), professor of medicine at St. Andrews, born in 1696 at Kirktonhall in the parish of West Kilbride, Ayrshire, was third son of John Simson of Kirktonhall, by his wife Agnes, daughter of Patrick Simson, minister of Renfrew. Robert Simson [q. v.], the mathematical professor, was his brother. In 1721 James Brydges, duke of Chandos, established a medical professorship in the university of St. Andrews, and on 10 Jan. 1722 Simson was admitted as its first incumbent. He held the chair until his death. In 1744 he was elected an honorary fellow of the Royal College of Physicians at Edinburgh (Charter and Regulations of the Royal College of Physicians, p. 95). He died on 30 April 1764 at St. Andrews.

About 1724 he married a daughter of Sir John Preston of Prestonhall, Fife, who was deprived of his estates in 1715. By her he had four sons and two daughters; of the former, James was professor of medicine at St. Andrews in succession to his father from 1764 to 1770. He was the author of: 1. ‘De re Medica,’ Edinburgh, 1726, 8vo. 2. ‘De Erroribus circa Materiam Medicam,’ 1726, 8vo. 3. ‘System of the Womb,’ London, 1729, 8vo. 4. ‘Enquiry on the Vital and Animal Actions,’ 1752, 8vo.